1 files changed, 34 insertions, 0 deletions
diff --git a/glw/debug.ha b/glw/debug.ha
new file mode 100644
index 0000000..2ffe3c4
--- /dev/null
+++ b/glw/debug.ha
@@ -0,0 +1,34 @@
+use strings;
+use types::c;
+use trace;
+
+use gl::*;
+
+fn debug_callback(
+	source: gl_enum,
+	type_: gl_enum,
+	id: uint,
+	severity: gl_enum,
+	length: i32,
+	message: nullable *const c::char,
+	user_data: nullable *opaque,
+) void = {
+	// (2024 note): I'm painfully aware of the data race present here:
+	// The GL driver can call this from another thread, and the stdlib has
+	// some non-thread-safe stuff in it that we use, in particular strconv.
+	// I've seen it happen at times, but it's pretty rare.
+	const message = (message: *const [*]u8)[..length];
+	const message = strings::fromutf8(message)!;
+	const message = strings::trimsuffix(message, "\n");
+	trace::debug(&trace::root, "gl: {}", message);
+};
+
+export fn init_debug_logging() void = {
+	let ctxflags = 0i32;
+	glGetIntegerv(GL_CONTEXT_FLAGS, &ctxflags);
+
+	if (ctxflags & GL_CONTEXT_FLAG_DEBUG_BIT: i32 != 0) {
+		trace::info(&trace::root, "opengl debugging is enabled");
+		glDebugMessageCallback(&debug_callback, null);
+	};
+};